Web slack preventer for multicolor perfecting printing presses



July 13 1926. 1,592,064

H. M. BARBER was SLACK PREVENTER FOR MULTICOLOR PEHFECTING PRINTING PRESSES Filed Oct. 31, 1925 INVENTOR ATTORNEYS atented duty 13, i

HOWARD M. BARBER, OF WESTERLY, RHODE ISLAND, ASSIGNOR TC 0. B. COTTRELL 8s SONS CGMPANY, OF WESTERLY, RHODE ISLAND, A CORPORATION 03: DELAWARE.

\VE'B SLACK BREVENTER FOR MULTICGLOB PERFECTING- PRINTING PRESSES.

Application filed Gctobcr 31, 1925. Serial No. 65,976.

In multi-color web perfecting printing presses where a greater numberot colors are printed on one side or" the web than on the other, for instance where two colors are printed by the first printing unit on one side of the web and four colors are printer by the second printing unit on the other side of the web, and where a common impression cylinder is provided in each printing unit, it has been customary to make the diameter of the impression cylinder of the first printing unit the same as theplate cylin ders of that unit and the diameter of the impression cylinder of the second printing' unit a multiple of the diameters of the impression cylinder of the first printing unit and the plate cylinders 01" the second printing unit.

This arrangement has made it difficult to produce clean and sharp printing in the second printing unit because of a tendency to slur, owing to the formation of a slack in the web between the two printing units.

1 have discovered that if the impression cylinders of the two units be made of the same diameters and their bearer diameters made the same, this slack in the web between the printing units is eliminated, slurring in the second printing unit is prevented and clean and sharp printing is ensured.

A practical example of my invention is represented in the accompanying drawing" in which the plate and impression cylinders oi the first printing unit are denoted by i, 2 and 3 and the plate and impression cylinders of the second printing unit are de noted by i, 5, 6, 7 and 8. The web which is passed through the two units is denoted by 9.

The plate cylinders of the two units the same diameters and the impression cylinders of the two units are the same diameters, in the present instance twice the diameters of the plate cylinders. It will be understood that the bearer diameters of the two impression cylinders must be the same to prevent the formation of slack in the web and to ensure clean and sharp printing in the second printing unit.

What I claim is 1. In a multi-color web perfecting printing press, two printing units arranged to p int more colors on one side of the web than on the other side thereof, the bearer diameters of the plate cylinders of both printing units being the same and the bearer diarieters oi the impression cylinders of both printing units being the same but multiples of the bearer diameters of their plate cylinders.

2 In a n'iulti-color web perfecting print-- ing press, two printing units, one arranged to print two colors on one side of the web and the other to print tour colors on the other side of the web, the bearer diameter of the plate cylinders of both printing units being the same and the bearer diameters ot the impression cylinders oi? both printing units being the same but twice the bearer diameters Ofillil' plate cylinders.

In testimony, that I claim the foregoing as my invention, I have signed my name this 28th day of October, 1925.

HOWARD M. BARBER. 

